1. Field of the Invention
The present invention relates to a powder molding apparatus for performing compression molding of powder material such as ceramics, foods, medicines, etc., using a mold formed of a die and upper and lower punch units.
2. Description of the Related Art
An example of such a powder molding apparatus is proposed in Japanese Patent No. 2695757, for example. This powder molding apparatus is configured so as to transport a rotating base upon which multiple molds are disposed over a powder supplying unit, compression molding unit, and product extracting unit, in that order, by means of a cam follower and track rail. This apparatus enables consecutive production of molded articles, thereby improving productivity.
Also, such powder molding apparatuses have in some cases conventionally used a rotating clamp mechanism which rotates in the same direction as the direction of compression driving as a clamp mechanism for the mold, from the perspective of doing away any play in attachment portion, regardless of whether manual or automatic.
On the other hand, in the event of sequentially transporting the mold to the powder supplying unit, compression molding unit, and product extracting unit, the mold is generally transported in a state wherein the upper and lower molds are fixed onto the same base plate. Accordingly, the position of the upper and lower molds are not affected by feeding precision or the like, and just determined by assembly precision.
Now, in order to further improve productivity with the above-described powder molding apparatus, an arrangement can be conceived wherein the transporting speed between the stages of the above rotating base is increased. However, increasing the rotating speed of the rotating base could conceivably result in molded articles falling or shifting due to the force of inertia or the like acting thereupon, and accordingly it has been supposed that high-speed transporting might not be able to be realized.
Also, with the above conventional powder molding apparatus, the structure involves restricting the position of the mold by means of a cam follower and track rail, so the forming process is determined by the track rail, and the mold moves with exactly the same profile regardless of what sort of mold is attached. Accordingly, the mold must be designed according to the track rail, which has been a problem in that the degree of freedom in the molding process has been small.
Also, with the above-described conventional mold clamp mechanism, in the event that the clamping direction is the same direction as that of the compression driving, if the molded article and the mold do not readily separate in the process of extracting the article from the mold following compression for example, trouble may occur such as separation not occurring with the clamp unit of the mold, the formed article being damaged at the time of separating, and so forth.
Further, with the structure wherein the above-described upper and lower molds are transported in a state of being fixed on the same base plate, the structure tends to become a massive configuration for integrally transporting the upper and lower molds. Accordingly, an arrangement can be conceived wherein only one of the upper and lower molds is transported, but in this case, the upper and lower molds must be positioned with each transportation, so there is demand for measures with regard to this issue.